Hangzhou Sumgen starts Phase 2 CD38 trial for ITP, joining Takeda's Mezagitamab
Sanritatug enters a subcutaneous safety and response study in immune thrombocytopenia, testing a CD38-blocking approach still unproven in this indication.
Executive Summary
- Hangzhou Sumgen Biotech opened a Phase 2 trial testing its subcutaneous CD38-blocking antibody in patients with primary immune thrombocytopenia who did not respond to first-line treatment.
- The trial places sanritatug against a small set of CD38-directed programs in this indication, with Takeda's mezagitamab already running a later-stage study.
- Sanritatug is being tested across more than one autoimmune indication at once, indicating the sponsor is betting on CD38 depletion as a mechanism that extends beyond a single disease.
- The study is designed to establish safety and an early platelet-response signal, not to support registration on its own.
The trial
The study, registered as NCT07710248 and titled the SG301-SC Injection Safety Study, will enroll 60 adults with primary immune thrombocytopenia who failed or relapsed after glucocorticoids or IVIG. Patients must have platelet counts below 30x10^9/L across at least two pre-dose assessments, and prior treatment targeting CD38 is an exclusion criterion. The trial uses a triple-masked, randomized, three-arm design and delivers sanritatug subcutaneously. It started recruiting on June 11, 2026, in China, with a primary completion date of May 17, 2027. NCT07710248SG301-SC Injection Safety Study in Subjects With Primary ITP PatientsNCT07710248
What it will measure
The registered primary outcomes are the incidence of treatment-emergent adverse events graded by CTCAE 6, tracked through 24 weeks, and the overall platelet response rate at week 8. That pairing makes this a safety and early-efficacy study: it is built to establish tolerability of subcutaneous dosing and an initial signal of platelet recovery, not to support a standalone approval. A second-line or later population that has already failed steroids and IVIG sets the bar for what counts as a response in a population where the disease has already resisted standard treatment. NCT07710248SG301-SC Injection Safety Study in Subjects With Primary ITP PatientsNCT07710248
The competitive field
CD38-targeted mechanisms are established in multiple myeloma, where several monoclonal antibodies, bispecifics, and a small molecule already carry approvals, but none of those approvals extend to immune thrombocytopenia. Inside ITP specifically, the CD38 field is sparse: only two active industry trials target CD38 in this indication, sanritatug's own program and Takeda's mezagitamab, which is running a Phase 3 follow-up study with a target completion in mid-2029. Takeda's trial is the closest direct comparator, sharing both the CD38 target and monoclonal antibody modality. The rest of the ITP landscape is mechanistically distinct: Qilu Pharmaceutical's QL0911 targets the TPO receptor and is already in Phase 3, and Sanofi's rilzabrutinib targets BTK, also in Phase 3. Given that no CD38-targeted therapy has yet reported a resolved outcome in ITP, the bar this program and Takeda's face is establishing that CD38 depletion produces a platelet response durable enough to justify displacing existing second-line options.
Sponsor strategy
Hangzhou Sumgen is developing sanritatug in more than one autoimmune indication concurrently: a separate Phase 2 trial tests the same drug in systemic lupus erythematosus. The sponsor's broader pipeline includes ten trials across recruiting, active, and terminated status, with five currently recruiting. Running CD38 depletion in parallel across ITP and lupus points to a strategy of testing one mechanism against multiple B-cell and plasma-cell-driven autoimmune diseases rather than committing early to a single indication.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.